Transplantation Of Brain Tissue Research Articles

Improvement of Rat Spinal Cord Injury Following Lentiviral Vector-Transduced Neural Stem/Progenitor Cells Derived from Human Epileptic Brain Tissue Transplantation with a Self-assembling Peptide Scaffold

Spinal cord injury (SCI) is a disabling neurological disorder that causes neural circuit dysfunction. Although various therapies have been applied to improve the neurological outcomes of SCI, little clinical progress has been achieved. Stem cell–based therapy aimed at restoring the lost cells and supporting micromilieu at the site of the injury has become a conceptually attractive option for tissue repair following SCI. Adult human neural stem/progenitor cells (hNS/PCs) were obtained from the epileptic human brain specimens. Induction of SCI was followed by the application of lentiviral vector-mediated green fluorescent protein–labeled hNS/PCs seeded in PuraMatrix peptide hydrogel (PM). The co-application of hNS/PCs and PM at the SCI injury site significantly enhanced cell survival and differentiation, reduced the lesion volume, and improved neurological functions compared to the control groups. Besides, the transplanted hNS/PCs seeded in PM revealed significantly higher migration abilities into the lesion site and the healthy host tissue as well as a greater differentiation into astrocytes and neurons in the vicinity of the lesion as well as in the host tissue. Our data suggest that the transplantation of hNS/PCs seeded in PM could be a promising approach to restore the damaged tissues and improve neurological functions after SCI.

СОВРЕМЕННЫЙ ВЗГЛЯД НА ПРОБЛЕМУ РАННЕЙ ДИАГНОСТИКИ ПРИОННЫХ ЗАБОЛЕВАНИЙ (ОБЗОР ЛИТЕРАТУРЫ)

Прионные заболевания составляют группу смертельных нейродегенеративных болезней человека. Уникальность заболеваний заключается в ятрогенном, спорадическом или наследственном способе передачи. В связи с возможностью ятрогенного способа возникает вопрос о ранней доклинической диагностике прионных болезней для последующего уменьшения рисков возможного инфицирования здоровых людей. В результате длительного инкубационного периода и трансмиссивности прионного белка невозможно определить уровень распространенности заболевания и принять адекватные профилактические мероприятия. Существует вероятность заражения любого из пациентов, получавших компоненты крови, трансплантацию тканей головного мозга. Постепенная разработка новых неинвазивных методов диагностики позволяет выявить наличие прионного белка до появления клинических симптомов и предотвратить дальнейшее заражение.

Targeted Transgenic RNAi Knockdown of Cell Fate Determinants Induces Neoplastic Tumor Growth and Metastasis in a Drosophila Transplantation Model of Neural Stem Cell Derived Cancer

Genetic models such as Drosophila have sophisticated transgenic and molecular genetic tools available to investigate proliferation control in normal and tumorigenic neural stem cells. In this report, we adapted a targeted transgenic RNAi knockdown approach based on the Gal4/UAS expression system to the study of neoplastic tumor formation and metastatic growth in the Drosophila brain tissue transplantation model. Transgenic RNAi driven knockdown of numb, brain tumor (brat) and prospero (pros) in all neuroblasts (type I and type II) resulted in a high incidence of neoplastic tumor formation after transplantation that was comparable to that of loss-of-function mutations in these cell fate determinants. RNAi knockdown of numb and brat specifically restricted to type II neuroblast lineages also resulted in tumor formation after transplantation. A marked temperature dependence of tumor formation after transplantation was documented and quantified for RNAi-induced knockdown of numb, brat and pros. An in vivo assay for micrometastasis formation in ovarioles revealed significant metastatic potential of transplanted overproliferating brain tissue induced by RNAi knockdown of these cell fate determinants. These findings establish the foundation for RNAi-based investigations of the mechanisms which underlie the proliferation, invasion and metastastic potential of neural stem cell induced tumors in the Drosophila model.

Analysis of the Methodology of Rabbit's Brain Tissue Transplantation Experiment

Analysis of the Methodology of Rabbit's Brain Tissue Transplantation Experiment

Importance of stoichiometry in cells science: iPSC, CNS leukocytes, and more

the hope of becoming the source and basis of sideeffect–free ‘‘medication’’ and repair of deficits in our body,stem cells have been, for a few decades, of interest in basic cellresearch, regenerative medicine, and public opinion. Cytome-try was from the beginning a guiding technology in thisendeavor. The substantial past and present scientific interest isreflected by the fact that publications on stem cells and theirunequivocal identification are the ‘‘best sellers’’ regarding cita-tion and download rates also in the cytometry-focused litera-ture (1). Nevertheless, stem cell therapy still plays a minor rolein clinical practice. The main stem cell therapy is allogenic orautologous bone marrow transplantation in cancer or insevere life-threatening autoimmune diseases such as rheuma-toid arthritis. This transplantation is either done by crudebone marrow allografting or by using purified (i.e., sorted orotherwise enriched) material.Another far less frequent application is transplantation offetal brain tissue in Parkinson’s disease, rendering (temporary)relief from the symptoms. Fetal brain transplant in Hunting-ton’s disease was far less successful as indicated by clinicaltrials enrolling a limited number of patients. In addition,transplantation of parts of the fetal brain is a continuing issueof ethical concern. One of the reasons for the limited applica-tion of stem cell therapy in regenerative medicine is the limita-tion of appropriate cell sources. Mesenchymal stem cells fromfatty tissue (2), as one example, can be relatively easily har-vested but may be limited in their regenerative abilities.Consequently, the discovery of embryonic pluripotentstem cells has led to both a great deal of activity and hype inresearch for novel cell-based therapies. As ethical issuesinvolved in using embryonic stem cells exist, only a limitednumber of countries equipped with appropriate high-endresearch knowledge and technology can embrace these cells fortherapy development.Therefore, the discovery of inducible pluripotent stemcells (iPSCs)—somatic cells (of in principle any type) that canbe reprogrammed by the transfection of a limited number oftranscription factors to become pluripotent—was an impor-tant breakthrough. By their creative and diligent work, thegroup of Shinya Yamanaka from Kyoto University in Japandiscovered that the transfection of only four genes was suffi-cient to reprogram somatic cells to become iPSCs and formany possible cell type of an organism (3).How to optimize the process of transfection to producemaximum numbers of reprogrammed cells and how to per-form appropriate quality control of yield and cell type remainsa central issue. Tiemann and coworkers from Hannover andM€unster in Germany (this issue, page 426) developed a poly-chromatic flow cytometry approach by attaching each of thefour transfected transcription factors (Oct4, c-Myc, Sox2, andKlf4) to four different fluorescent proteins. Quadruplet posi-tive cells contain the reprogrammed iPSCs that can then besorted and cloned. By testing different stoichiometric combi-nations of these transcription factor expression levels,the authors were able to optimize iPSC yield and quantitateoptimal transcription factor levels.The importance of polychromatic cytometry has beenapplied to identify unusual biological material in the pri-mate brain. Bischoff from the University of G€ottingen,Germany and colleagues (this issue, page 436) focusedtheir interest on cells of the immune system infiltratingthe brain. The quantity and composition of these cells canrender information on inflammation processes in neuro-logical diseases and also in stem cell transplantation,

Function Recovery after Transplantation of Fetal Brain Tissue into Injured Spinal Cord in Experimental Rats

Rakei, S.M., Rahmanian, A., Saffarian, A., Shafeian, R. and Mehrabani, D. 2009. Function recovery after transplantation of fetal brain tissue into injured spinal cord in experimental rats. J. Appl. Anim. Res., 36: 303–306. To determine the effect of transplantation of fetal brain tissue on regeneration of injured spinal cord and the limb function recovery, forty 30-week old male Sprague-Dawley 350–450 g rats were randomly and equally divided into two groups. In 5 pregnant rats the fetuses were removed and the embryonic brain tissues were sectioned into 0.05 mm segments under microscope. The vertebral column was exposed and a 0.1 mm segment of spinal cord medulla at the T10-T11 level was completely dissected in all rats of both groups. A 0.05 mm segment of rat fetus brain was implanted into the injured section of spinal cord of all rats in the case group. No further intervention was done in the control group. After 24 h lower extremity paraplegia was confirmed in all rats. After six weeks, no locomotor improvement was seen in the control group (Basso-Beattie-Bresnahan locomotor rating scale, BBB=0). 15% of rats in the case group had some degrees of recovery from spinal cord injury. Our findings suggest that fetal neural transplants could potentially be an effective surgical intervention for treatment of SCI even though more investigations are warranted.

Expression of PCNA and Bcl-2 in the traumatic brains implanted with embryonic brain tissue in rats

To investigate the expression of PCNA and Bcl-2 in the traumatic brain area transplanted with embryonic brain tissue in rats. The cerebral contusion of rats was induced by dropping weight. The homogenates of embryonic brain tissue were transplanted into the traumatic brain area two weeks after injury. All rats were sacrificed 6 weeks after injury (4 weeks after transplantation), and their brains were examined histologically. The expressions of PCNA and Bcl-2 in the brains were analyzed by immunohistochemical methods. The histology of brain presented the capillary and glia proliferation, especially in the transplantation group. No significant difference was found in the expression of PCNA between two groups. However, Bcl-2 was overexpressed in the transplantation group. The transplantation of the embryonic brain tissue enhances the expression of Bcl-2, which may play a neuroprotective role following traumatic brain injury.

Stem cell transplantation

Stem cell transplantation

Neural Transplantation: An Introduction

Although there are many scientific and philosphical reasons to study brain, for William J. Freed, the most compelling reason to study brain is to be able to repair brains of individuals with nervous systems injury or disease. Advances in repairing nervous system, as well as new data on brain development, growth and plasticity, have revolutionized field of brain research and given rise to technology of brain tissue transplantation. In this book Freed discussses what may and what may not be possible. The book covers two aspects of neural tissue transplantation research. One involved transplantation of particular cells to repair or augment specific neuronal systems. This technique could be useful for such conditions as Parkinson's disease, Huntington's disease, chronic pain and epilepsy. The other line of research concerns regeneration from injury, especially of spinal cord. After providing basic background on transplantation, brain structure and development, book discusses Parkinson's disease, use of transplants to influence localized brain functions, circuit reconstruction and genetic engineering and other future technologies.

Induction of a midbrain dopaminergic phenotype in Nurr1-overexpressing neural stem cells by type 1 astrocytes

The implementation of neural stem cell lines as a source material for brain tissue transplants is currently limited by the ability to induce specific neurochemical phenotypes in these cells. Here, we show that coordinated induction of a ventral mesencephalic dopaminergic phenotype in an immortalized multipotent neural stem cell line can be achieved in vitro. This process requires both the overexpression of the nuclear receptor Nurr1 and factors derived from local type 1 astrocytes. Over 80% of cells obtained by this method demonstrate a phenotype indistinguishable from that of endogenous dopaminergic neurons. Moreover, this procedure yields an unlimited number of cells that can engraft in vivo and that may constitute a useful source material for neuronal replacement in Parkinson's disease.

Anatomical distribution of glycoprotein 93 (gp93) on nerve fibers during rat brain development.

Recent studies have implicated glycoconjugates on the membrane of growth cones as the necessary markers and intermediaries for axonal recognition, axonal motility, and pathway development. One such glycoconjugate, glycoprotein 93 (gp93), has been characterized, but the relative distribution of gp93 has yet to be described for the embryonic brain. In this study, the anatomical distribution of gp93 has been analyzed at embryonic day 15 (E15) and E18, and on postnatal day 3 in the rat by using a polyclonal gp93 antibody. Furthermore, fetal brain tissue transplanted into the adult rat eye has been tested for gp93 immunoreactivity, since central noradrenergic neurons in brainstem transplants are known to provide a continuous source of growing axons, even in adult tissue. In general, a greater abundance of gp93 immunoreactivity is apparent in the earlier embryonic stages (E15 and E18), whereas less is seen in the postnatal brain. The regions showing unique dispersal patterns of gp93 are the neuroepithelium, cerebral cortex, septo-hippocampal pathways, brainstem, and midbrain. This study has therefore focused on these areas and found implications for gp93 distribution appearing in the early development of specific neuronal pathways. Moreover, axons stain densely for gp93 within brain tissue transplants. The presence of gp93 in areas of extensive axonal outgrowth in the normal brain and in transplants suggests that this antibody is used as an early marker for axonal growth. Furthermore, gp93 might be used to map normal development in order to improve our understanding of diseases arising from developmental abnormalities.

Transplantation of fetal brain tissue into the site of intracerebral hemorrhage in rats

The purpose of this study was to evaluate whether transplantation of fetal forebrain tissue into the hematoma site of rats with intrastriatal hemorrhage could improve the final neurological outcome. Nine to twelve days after collagenase-induced intracerebral hemorrhage, day 14 fetal forebrain fragments were transplanted into hematoma site. Quantitative measures of behavioral function were repeatedly evaluated until the rats were killed 10 weeks after grafting. Histology was used to assess the survival of the grafts and overall brain morphology. Surviving grafts were located in the residual cavity at the hematoma site. However, comparison of rats with live transplants to control rats with no transplant, sham transplant, or dead tissue transplant revealed no statistically significant differences in any of the motor tests.

Neurotransmitter and Amino Acid Analysis and Ultrastructural Observations of Fetal Brain Cortex Transplantation to Adult Rat Brain under the Effect of Dexamethasone

To conduct an investigation of fetal cortical tissue graft survival using transmission electron microscopy and analyzing neurotransmitters and amino acids and their function, with special reference to the effect of dexamethasone. Transplantation of fetal cortical brain tissue to 100 adult Wistar albino rats weighing 170 to 220 g was performed. The rats were divided into three groups. Only transplantation of fetal cortical brain tissue was performed in the first group (n=36). In the second group (n=48), dexamethasone was administered in addition to fetal cortical tissue transplantation. The third group (n=16) was used as the surgical control group. The rats were allowed to live for 6 weeks and were then decapitated. The grafts were examined by electron microscopy. Additionally, quantitative analyses of the neurotransmitters and amino acids of the grafts were conducted using high-pressure liquid chromatography. Electron microscopic observations revealed that the grafts were still surviving at the end of the 6th week in both groups. However, in the group that received dexamethasone, neurons and their organelles were better developed than in the group that did not receive dexamethasone. Concommitantly, results of quantitative analysis in the dexamethasone group revealed statistically extremely significant higher amino acid values for glutamic acid, aspartic acid, beta-alanine, and lysine and significantly higher values for gamma-aminobutyric acid, glutamine, glycine, and serine when compared to the nondexamethasone group. Dexamethasone is effective in increasing the survival and in developing the ultrastructural and functional outcome of transplanted neurons in fetal grafts.

The brain-mind quiddity: ethical issues in the use of human brain tissue for therapeutic and scientific purposes.

The use of human brain tissue in neuroscience research is increasing. Recent developments include transplanting neural tissue, growing or maintaining neural tissue in laboratories and using surgically removed tissue for...

Effect of embryonic brain tissue transplantation on structural changes in the rat brain after craniocerebral trauma

The effect of homotopic allotransplantation of embryonic cerebral cortex tissue on structural changes in the brain were studied on rats who had suffered a severe craniocerebral trauma (CCT) and subsequent traumatonesis of an injured region. Using Nissl and Golgi-Cox techniques, we showed that the presence of a viable graft in the cavity created by the traumatonesis procedure prevented formation of coarse gliofibrous expansions and extensive “dead zones” within the perifocal region of the injury locus. Transplantation performed immediately after the CCT and traumatonesis appeared to be most effective. In this case, the graft growth was more intensive and it was better integrated into the recipient's brain; branching of neurons in the graft was more abundant, and their dendrites were densely covered with spines. Thus, the use of early transplantation prevents the development of destructive and dystrophic changes evoked by severe CCT and can be regarded as a promising direction in neurosurgical practice.

Do brain tissue transplants alter personal identity? Inadequacies of some "standard" arguments.

Currently, brain tissue transplantations are being developed as a clinical-therapeutic tool in neurodegenerative diseases such as Parkinson's or Alzheimer's disease. From an ethical point of view, distinguishing between the preservation and an alteration of personal identity seems to be central to determining the scope for further application of brain tissue transplantation therapy. The purpose of this article is to review "standard" arguments which are used on the one hand by proponents to prove preservation of personal identity and by opponents on the other hand to prove that brain tissue transplantation results in an altered personal identity. Proponents and opponents are shown to use the same arguments, albeit with different presuppositions. These presuppositions concern the meaning of the term "identity", either numerical or qualitative, the definition of brain identity, either structurally or functionally, and the relationship between mental states, psychological functions and neurophysiological properties as criteria for personal identity. Furthermore the respective neurophysiological, clinical and philosophical evidence for the different presuppositions are discussed. It is concluded that evaluation of personal identity in brain tissue transplantation should not only rely on the "standard" arguments but, additionally, neurophysiological, clinical and philosophical implications should be discussed.

Development of an intact blood-brain barrier in brain tissue transplants is dependent on the site of transplantation

Transplantation of fetal septal forebrain tissue was performed to the anterior chamber of the eye, or intracranially to the rostral hippocampal formation in rats, to evaluate the impact of transplantation site on the development of an intact blood-brain barrier (BBB). The tissue was studied at 1,2,3, and 4 wk following transplantation by means of intravenous injection of Trypan blue, which is a vital stain not normally penetrating the BBB, as well as with an antibody specifically directed against the rat BBB, SM171. In the intraocular septal transplants, there was a significant leakage of Trypan blue 1 wk postgrafting, associated with a few laminin-immunoreactive blood vessels that did not contain any SM17I-immunoreactivity. However, at 2 wk postgrafting, the intraocular grafts exhibited an extensive plexus of thin-walled blood vessels expressing SMI71 immunoreactivity and no Trypan blue leakage. Thus, it appeared that a BBB had developed to some degree by 2 wk postgrafting in oculo. In the intracranial grafts, on the other hand, Trypan blue leakage could be seen as long as 3 wk postgrafting, and a dense plexus of blood vessels with SMI71 immunoreactivity was first seen at 4 wk postgrafting. Thus, the development of Trypan blue impermeability was delayed with 1 to 2 wk in the intracranial versus the intraocular grafts. Control experiments using psychological stress in adult rats as a means to transiently disrupt the BBB revealed that an increase in Trypan blue leakage correlated well with the disappearance of SMI71 immunoreactivity. Taken together, these studies demonstrate that the site of transplantation can influence the development of an intact BBB in neural tissue grafts.

Development of an intact blood-brain barrier in brain tissue transplants is dependent on the site of transplantation.

Transplantation of fetal septal forebrain tissue was performed to the anterior chamber of the eye, or intracranially to the rostral hippocampal formation in rats, to evaluate the impact of transplantation site on the development of an intact blood-brain barrier (BBB). The tissue was studied at 1,2,3, and 4 wk following transplantation by means of intravenous injection of Trypan blue, which is a vital stain not normally penetrating the BBB, as well as with an antibody specifically directed against the rat BBB, SM171. In the intraocular septal transplants, there was a significant leakage of Trypan blue 1 wk postgrafting, associated with a few laminin-immunoreactive blood vessels that did not contain any SM17I-immunoreactivity. However, at 2 wk postgrafting, the intraocular grafts exhibited an extensive plexus of thin-walled blood vessels expressing SMI71 immunoreactivity and no Trypan blue leakage. Thus, it appeared that a BBB had developed to some degree by 2 wk postgrafting in oculo. In the intracranial grafts, on the other hand, Trypan blue leakage could be seen as long as 3 wk postgrafting, and a dense plexus of blood vessels with SMI71 immunoreactivity was first seen at 4 wk postgrafting. Thus, the development of Trypan blue impermeability was delayed with 1 to 2 wk in the intracranial versus the intraocular grafts. Control experiments using psychological stress in adult rats as a means to transiently disrupt the BBB revealed that an increase in Trypan blue leakage correlated well with the disappearance of SMI71 immunoreactivity. Taken together, these studies demonstrate that the site of transplantation can influence the development of an intact BBB in neural tissue grafts.

Overexpressing Cu/Zn superoxide dismutase enhances survival of transplanted neurons in a rat model of Parkinson's disease.

A high survival rate of grafted dopamine neurons is crucial for reversing neurological deficits following brain tissue transplantation in Parkinson's disease. For unknown reasons the survival rate of transplanted dopamine neurons is only around 10% in experimental animals. The hypothesis that oxidative stress causes the loss of transplanted neurons was tested by grafting neurons from transgenic mice that overexpress Cu/Zn superoxide dismutase. Compared with the survival of those taken from non-transgenic littermates, the survival was 4 times higher for the transgenic dopamine neurons with a concomitant more extensive functional recovery. The results provide direct support for the free radical hypothesis of dopaminergic neuron death in brain tissue grafting.

The LHRH pulse generator: A mediobasal hypothalamic location

The location and mechanism of LHRH pulse generator are discussed based on our series of experiments. Suckling stimulus is a novel stimulus that inhibits LH pulses without any cooperation from ovarian steroids, unlike other stimuli such as stress, photoperiod etc. It is directly involved in suppressing the activity of the LHRH pulse generator. The information from teats suckled by pups or babies is conveyed dorsally to the mediobasal hypothalamus (MBH), where the LHRH pulse generator may be located. Experiments using various types of deafferentation and fetal brain tissue transplantation confirmed that the LHRH pulse generator is located in the MBH and suggested that LHRH pulse generator consists of nonLHRH neurons. Endogenous excitatory amino acid is one of the possible neurotransmitters that regulate LHRH release at the nerve terminal in ME.